http://dtcsearch.com/P0740/

Start there

thats what im going to do next, trace all the wires back to the pcm and make sure each has continuity. I bought the harness from a local company, SSP wiring I believe the name was. Seems like a really nice harness. Everything is new and well done. Im hoping a pin got pushed out of the connector or something simple.

This may be a stupid question, but does the trans/pcm need an electrical input from the shifter to know what gear its been placed into? I only ask becuase Iam using the factory 1980 camaro shifter setup. There is no PNP switch or anything, just the shifter cable. I just know the 4th gen camaros had an electical switch mounted on the shifter itself and I want to make sure this isnt why Im having this problem.

What year ECM are u using and what is the part# ? What year is the Trans? 4l60, 4l80, 4l70?? Roger

Well I figured it out finally, the company I bought the harness from screwed up and put the wires in wrong in the main trans connector. Luckily I had a factory harness to compare to. The wires were put in 180 degrees backwards in the connector. I had to removed them all, turn the connector 180 and reinstall them. Everything seems to work fine now. I haven't gotten into 3rd or 4th gear yet but it seems to be shifting perfectly fine. Now all I have to do is figure this misfire out....

Great news and glad you were able to figure it out. Make sure you post some burn out pics once you get it out

:cheers:

So far on the misfire I have; verified good fuel pressure 58-60 psi, checked the plug wires and coil. Swapped the coil/plug wire and the misfire didnt follow the coil. I used a noid light to check the inctor circuits, removed the coil sub-harness and checked all the wires for continuity/resisance, pulled the valve cover and made sure the valves were opening properly, removed the plugs (#7 is clean and shows good continuity and isnt broken internally) I fired up the engine for a few seconds and touched each header and found that cylinder 7 is the only cold one. So far everything I have looked at checks out fine. The only things I havent done is verified good coil driver circuit for cylinder 7 or checked for a physical clog in the injector. Any other ideas??

If the motor sat for any length of time, that injector could be plugged. I could not get my LS1 to start after the swap. I checked everything & nothing was out of order. I couldnt figure it out. I pulled all the injectors and soaked them in sea foam overnight. Put them in & it fired right away. Have you checked that plug- is it wet with fuel? Bad plug possibly? Scott

Well I went through the harness wires (power and signals to coil connector) all the connections and wires were good. Just to be sure I pulled the wires out of a GM harness that I had and ran them instead of the wires that came with the harness. Still no change, miss on cylinder 5. I switched the coil out with one I had and it seemed to not be misfiring as bad. Maybe both my coils are bad?? I dont know what the odds of that are but Im out of ideas at this point. I think Im going to check the injectors next. I know they did sit for a while, its possible they got clogged.